Only text of wp-config is shown

Hi all,

this is know my third intallation of wordpress but I′ve never seen this before. I changed wp-config-sample and put my dates in the correspomding fields and saved the hole under wp-config. After that I uploades all files via FTP to my Webspace and tried to start ….wp-admin/install-php. But all I see is the text of the wp-config file, the installation doesn`t start.
How can that be?
Hope anybody as an answer for me.

PHP5 is running, datas in the wp-config are correct.